Photocatalytic activity of bismuth germanate Bi12GeO20 powders

The photocatalytic activity of sillenite Bi12GeO20 powders prepared with a chemical solution decomposition technique was studied for the first time. The photocatalytic activity of the as-prepared Bi12GeO20 was evaluated using methyl orange as a model organic compound. It was found that the prepared Bi12GeO20 powders with very low specific surface area exhibit outstanding photocatalytic activity in the photocatalytic degradation of methyl orange. The optical absorption in visible light region is due to the intrinsic (Bi-Ge(3+) + V-o(+)) defect in the Bi12GeO20 crystal, and the high photocatalytic activity was attributed to the high mobility of the photo-generated carriers. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.